Catalytic oxidation of diclofenac by hydroxylamine-enhanced Cu nanoparticles and the efficient neutral heterogeneous-homogeneous reactive copper cycle

Xiang, Wei; Zhou, Tao; Wang, Yifan; Huang, Mingjie; Wu, Xiaohui; Mao, Juan; Lu, Xiejuan; Zhang, Beiping

doi:10.1016/j.watres.2019.01.024

Cited by 92 publications

(28 citation statements)

References 45 publications

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“…The reduction of Cu(II) to Cu(I) was reported for the HA/Cu(II) reaction . Similarly, we anticipate that Cu(I) would also be produced here in TDO/Cu(II).…”

Section: Resultssupporting

confidence: 77%

“…The reduction of Cu(II) to Cu(I) was reported for the HA/ Cu(II) reaction. 27 Similarly, we anticipate that Cu(I) would also be produced here in TDO/Cu(II). In the absence of DTZ, Cu(I) was detected at low concentrations (<2 μM, 20% of the Cu(II) dosed) when the reactor was open to air (Figure 5a).…”

Section: ■ Results and Discussionmentioning

confidence: 82%

“…In the presence of oxygen, the self-decomposition of TDO generates O 2 •– through eqs –. The dismutation of O 2 •– produces H 2 O 2 , which can be further accelerated by Cu(II). ,,− At neutral pH, TDO moderately decomposed (Figure S2 in the SI), and a small amount of H 2 O 2 was detected during the TDO/Cu(II) reaction (Figure S4 in the SI). Fenton-like reactions usually occur between Cu(II) and H 2 O 2 , ,− where • OH or Cu(III) are probable major oxidants.…”

Section: Resultsmentioning

confidence: 99%

“…Cu(II) is active in accelerating many oxidation reactions in water/wastewater. Trace Cu(II) (i.e., at several micromoles, which is close to the background copper concentrations of some municipal wastewater − and below drinking water quality standards (15–20 μM)) is able to homogeneously activate oxidants such as H 2 O 2 and persulfates to generate reactive oxidants. − The reaction of Cu(II) with hydroxylamine (HA) also produces H 2 O 2 and Cu(III) in sequence, which is able to degrade some pollutants. , The step of Cu(II) reduction to Cu(I) was proposed to be critical in initiating Fenton-like reactions. − In contrast to oxidation, reduction reactions mediated by trace Cu(II) are rarely reported for pollutant removal.…”

Section: Introductionmentioning

confidence: 99%

“…23−25 The reaction of Cu(II) with hydroxylamine (HA) also produces H 2 O 2 and Cu(III) in sequence, which is able to degrade some pollutants. 26,27 The step of Cu(II) reduction to Cu(I) was proposed to be critical in initiating Fenton-like reactions. 28−30 In contrast to oxidation, reduction reactions mediated by trace Cu(II) are rarely reported for pollutant removal.…”

Section: ■ Introductionmentioning

confidence: 99%

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Thiourea Dioxide Coupled with Trace Cu(II): An Effective Process for the Reductive Degradation of Diatrizoate

Wang

et al. 2021

Environ. Sci. Technol.

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Diatrizoate, a refractory ionic iodinated X-ray contrast media (ICM) compound, cannot be efficiently degraded in a complex wastewater matrix even by advanced oxidation processes. We report in this research that a homogeneous process, thiourea dioxide (TDO) coupled with trace Cu(II) (several micromoles, ubiquitous in some wastewater), is effective for reductive deiodination and degradation of diatrizoate at neutral pH values. Specifically, the molar ratio of iodide released to TDO consumed reached 2 under ideal experimental conditions. TDO eventually decomposed into urea and sulfite/sulfate. Based on the results of diatrizoate degradation, TDO decomposition, and Cu(I) generation and consumption during the TDO–Cu(II) reaction, we confirmed that Cu(I) is responsible for diatrizoate degradation. However, free Cu(I) alone did not work. It was proposed that Cu(I) complexes are actual reactive species toward diatrizoate. Inorganic anions and effluent organic matter negatively influence diatrizoate degradation, but by increasing the TDO dosage, as well as extending the reaction time, its degradation efficiency can still be guaranteed for real hospital wastewater. This reduction reaction could be potentially useful for in situ deiodination and degradation of diatrizoate in hospital wastewater before discharge into municipal sewage networks.

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“…The reduction of Cu(II) to Cu(I) was reported for the HA/Cu(II) reaction . Similarly, we anticipate that Cu(I) would also be produced here in TDO/Cu(II).…”

Section: Resultssupporting

confidence: 77%

Section: ■ Results and Discussionmentioning

confidence: 82%